memoQ completely ignores sublanguages when it is working with translation memories. With variants of English, here is what this means:

In a project from English into German, translation memories from English, English (US), and English (UK) will all return matches. The match rate will not be different if the same segment occurs in two TMs with different sublanguages. When it lists the results, memoQ will not even give priority to the TM with the matching sublanguage. Instead, TMs that return the same match will be listed in alphabetical order of their names.

In a project from English (US) into German, the same happens.

In a project where the target language is English, memoQ will not distinguish TMs by the sublanguage of their target languages.

In addition, memoQ will not have a problem updating or adding segments to a translation memory that has a different sublanguage either for the source or the target language.